Shareholder's Equity, Warrants (Details) - USD ($) $ / shares in Units, $ in Thousands				2 Months Ended	12 Months Ended
	Jan. 10, 2017	Nov. 03, 2016	Jul. 26, 2016	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Proceeds from exercise of warrants					$ 1,989	$ 0
Warrants outstanding					0	1,843
Change in fair value of warrant liability					1,475	$ 818
Expected stock price volatility		41.40%	78.00%
Risk-free interest rate		1.33%	0.94%
Expected warrant option life		5 years 6 months	3 years 6 months
Minimum [Member]
Class of Stock [Line Items]
Expected stock price volatility						55.30%
Risk-free interest rate						1.47%
Expected warrant option life						3 years 1 month 6 days
Maximum [Member]
Class of Stock [Line Items]
Expected stock price volatility						49.80%
Risk-free interest rate						1.96%
Expected warrant option life						5 years 3 months 18 days
Replacement Warrants [Member]
Class of Stock [Line Items]
Warrants outstanding					$ 500
Expected dividend yield					0.00%
Expected warrant option life					5 years
Replacement Warrants [Member] | Minimum [Member]
Class of Stock [Line Items]
Expected stock price volatility					49.65%
Risk-free interest rate					1.95%
Replacement Warrants [Member] | Maximum [Member]
Class of Stock [Line Items]
Expected stock price volatility					50.38%
Risk-free interest rate					1.97%
Series B Convertible Preferred Stock [Member] | Investor Warrants [Member]
Class of Stock [Line Items]
Warrants issuance cost			$ 0
Warrants to purchase shares of common stock (in shares)			6,149
Exercise price of warrants (in dollars per share)			$ 564
Warrants exercisable period					36 months
Period warrants became exercisable from closing date					6 months
Series D Convertible Preferred Stock [Member] | Investor Warrants [Member]
Class of Stock [Line Items]
Warrants issuance cost	$ 0
Warrants to purchase shares of common stock (in shares)	1,961
Exercise price of warrants (in dollars per share)	$ 108
Warrants exercisable period					60 months
Period warrants became exercisable from closing date					6 months
Series C and D Convertible Preferred Stock [Member] | Investor Warrants [Member]
Class of Stock [Line Items]
Warrants issuance cost		$ 0
Warrants to purchase shares of common stock (in shares)		35,295
Exercise price of warrants (in dollars per share)		$ 108
Adjusted exercise price of warrants (in dollars per share)		$ 102
Warrant Exercise Agreement [Member] | Original Warrants [Member]
Class of Stock [Line Items]
Proceeds from exercise of warrants				$ 2,000
Warrants outstanding					$ 0
Relinquished amount of warrants					$ 100
Warrant Exercise Agreement [Member] | Replacement Warrants [Member]
Class of Stock [Line Items]
Warrants to purchase shares of common stock (in shares)				43,396
Warrant Exercise Agreement [Member] | Replacement Warrants [Member] | Minimum [Member]
Class of Stock [Line Items]
Exercise price of warrants (in dollars per share)				$ 34.6
Warrant Exercise Agreement [Member] | Replacement Warrants [Member] | Maximum [Member]
Class of Stock [Line Items]
Exercise price of warrants (in dollars per share)				$ 99.8